Fig. 32.
The most suitable one now in use is the Oechsle's must scale, constructed on the principle that the instrument sinks the deeper into any fluid, the thinner it is, or the less sugar it contains. Fig. 32 shows this instrument, "which is generally made of silver, or German silver, although they are also made of glass. A, represents a hollow cylinder—best made of glass, filled with must to the brim, into which place the must scale B. It is composed of the hollow float a, which keeps it suspended in the fluid; of the weight c, for holding in a perpendicular position; and of the scale e divided by small lines into from fifty to one hundred degrees. Before the gauge is placed in the must, draw it several times through the mouth, to moisten it—but allow no saliva to adhere to it. When the guage ceases to descend, note the degree to which it has sunk; after which press it down with the finger a few degrees further, and on its standing still again, the line to which the must reaches, indicates its so-called weight, expressed by degrees." The must should be weighed in an entirely fresh state, before it shows any sign of fermentation, and should be free from husks, and pure.
This instrument, which is indispensable to every one who intends to make wine, can be obtained in nearly every large town, from the prominent opticians. Jacob Blattner, at St. Louis keeps them for sale.
The saccharometer will indicate the amount of sugar in the must, and its use is so simple, that every one can soon become familiar with it. The next step in the improvement of wines was to determine the amount of acids the must contained, and this problem has also been successfully solved by the invention of the acidimeter:
THE ACIDIMETER AND ITS USE.
"The first instrument of this kind which came into general use, was one invented by Dr. Otto, and consists of a glass tube, from ten to twelve inches in length, half an inch in width, and closed at the lower end. Fig. 33 shows Otto's Acidimeter.
"The tube is filled to the partition line a, with tincture of litmus. The must to be examined, before it has begun to ferment is then poured into the tube, until it reaches the line 0. The blue tincture of litmus, which would still be blue, if water had been added, is turned into rose-color by the action of the acids contained in the must.
Fig. 33.